Index: sky/examples/game/lib/sprite.dart |
diff --git a/sky/examples/game/lib/sprite.dart b/sky/examples/game/lib/sprite.dart |
index 84bdf88bff65aca981570091fe4700f40199e131..c730056eb34b79fb98de5e204b6e87dea03444e0 100644 |
--- a/sky/examples/game/lib/sprite.dart |
+++ b/sky/examples/game/lib/sprite.dart |
@@ -22,6 +22,7 @@ class Sprite extends NodeWithSize { |
double get opacity => _opacity; |
void set opacity(double opacity) { |
+ assert(opacity != null); |
assert(opacity >= 0.0 && opacity <= 1.0); |
_opacity = opacity; |
} |